I've done these kinds of exercises a number of times at Gunsite. A major difference was that the targets included "no shoots", and a truly major difference was that I hadn't set the targets and therefore did not know where they were. Another important part of doing the exercise was that it was done with an instructor.

What a "clearing" exercise is primarily about is (1) moving through the structure making the best use of cover and concealment; (2) identifying and engaging threats while exposing oneself as little as possible; and (3) distinguishing threats from innocents.